In the combustion chamber housing according to the German Patent Application P 42 22 391.1, the compressor air flows through a lateral inlet elbow in the shape of an arc into a contracting intake heart and enters the interior of the combustion chamber housing through the perforated cone, flowing in the upward direction there, past the conical injector tube, and reaching the burner and the flame tube there.
The injector tube is attached to the lower part of the flame tube by an intermediate ring, and the flame tube has a refractory lining of ceramic bricks.
The compressor air drawn in from the circular annular channel or intake heart consequently enters the flame tube as primary air through the burner and also enters the inner combustion space of the combustion chamber through secondary air openings in the injector tube. The secondary air openings may be located in both the mixing housing and the flame tube.
According to another combustion chamber housing design, the intake cross section of these secondary air openings in the flame tube can be regulated by means of an adjusting ring, and the secondary airflow cross sections are modified by rotating the adjusting ring with an electromechanical or hydraulic device.
The primary air excess ratio .lambda. of the burner shall be maintained at a nearly constant value for a predetermined work or performance range by adjusting the adjusting ring.
The movable parts of the adjusting ring are located in the compressor air flow between the combustion chamber housing and the flame tube, and the drive unit is located outside the combustion chamber housing.
The space requirement for the arrangement of the adjusting ring within the compressor air flow between the flame tube and the combustion chamber housing is so large that the design of the combustion chamber housing must be modified in this area. It also becomes necessary to have an expensive and complicated sealing of the drive in the wall of the combustion chamber housing.
Finally, the free flow cross section is reduced by the built-in parts of the adjusting ring, and considerable flow losses develop. In addition, high requirements are imposed on the mechanical processing of the moving parts.